Electric discharge apparatus



Jan. s, 1943.

Inventor* Lysle W Mortn, bg J His Attorney.

Patented Jan. 5, 1943 @FECE- i ELECTRIC DISCHARGE APPARATUS Lysle W.Morton, Schenectady, N. Y., assigner to General Electric Company, acorporation of New York My invention relates to electric dischargeapparatus, and more particularly to an improved exhaust and liquidreturn system 4for a plurality of electric discharge devices each.employing a liquid electrode.

There has been a marked trend towards the use of electric dischargedevices of the type comprising a, single anode and a liquid cathodemounted within a single container. t is readily appreciated that withthe increased number of containers employed in installations utilizingdevices of the above type it is desirable to employ a single exhaustsystem for a plurality oi discharge devices. However, simply connectingthe units to a common exhaust header has had some disadvantages from anoperating standpoint. For example, in some cases there is a tendency formore of the liquid, forming the cathodes, to collect in one of thesedevices than in the others so that satisfactory operation of all theunits is not obtained. In accordance with the teachings of my inventionI provide an improved system in which aplurality of electric dischargedevices are maintained exhausted and the cathodes are maintained at auniform level by a, simple and inexpensive exhaust and liquid returnsystem. l

It is an object ofmy invention to providevnew and improved electricdischarge apparatus.

3 It is `another, object of my invention to provide an improved exhaustand mercury return system for a plurality'o'f electric dischargedevices.

It is still another` object of my invention to provide an improvedsystemembodying a plurality of electric discharge devices having acommon exhaust system which insures a uniform level of the liquidelectrodes employed in the discharge devices.

In accordance with the illustrated embodiment of my invention aplurality o f electric discharge devices, each comprising aV vesselwithin which are mounted an anode and a mercury pool type cathode, areinterconnected by a ccnduit system communicating with each of thevessels below the level of the liquid cathodes and by a second conduitsystem communicating with each of the vessels preferably near the upperends thereof. The second conduit system is connected to the low pressureside of a mercury condensation pump which is provided with a liquidreturn for returning condensed mercury to the last mentioned conduitsystem. The high pressure side of the mercury condensation pump isconnected through a vacuum tight valve and receiver tank to the lowpressure side of a second pump of any-desired type which maintains alowMy invention will be better understood by reference to the followingdescription taken in connection with the accompanying drawing and itsscope will be pointed out in the appended claims. In the drawing, Figs.l, 2 and 3 are respectively a front elevational view, a plan view and anend elevational view of one embodiment of my invention.

Referring to the drawing, I have shown my invention applied to a systemfor exhausting the vesselsand maintaining the levelof the cathodes `of asystem comprising electric discharge dej vide a conduit rsystemcommunicating with each vices lil to i5, inclusive.V As illustrated,each of the discharge devices is of the type comprising a vessel whichmay be in the form of a metal container and within which are mounted theelectrodes of thedevice. As illustrated in Fig. 3, each device includesan anode i6 and a cathode H comprising a pool of conductive liquid suchas mercury.A Av suitable .starting electrode (not shown) is mounted ininsulated relation with respect to the container of the device by meansof suitable electrode support and seal I8. 'Ihe devices l@ to I5,inclusive, are mounted on a suitable supporting frame iS made up of laplurality yof channel irons. yThe containers of the devices lu to l5lare, supported on the frame I9 by suitable metal feet 2G which aresecured to the containers and to the channel iron framework. In devicesof this character the containers are usually at' the potential of thecathodes, and as illustratedl in the drawing, a cathode bus 2| isconnected with the cathodes by conducting bars 22 which interconnect thecontainers and the cathode bus. The external electrical connections withthe anode I6 are made with the anode studs 23 which extend through andare supported in insulated relation with respect to a sleeve 24 o-n thecover of the container.

In order that all of the vessels may be kept exhausted by `a singleevacuating system'I proof the vessels above the level of the liquidcathcdes and preferably communicating with the vessels near the topsthereof. As illustrated, the conduit system comprises a manifold 25 anda plurality of individual conduits 26 each cornmunicating at one endwith the manifold and at the other end with the interior of theoontainer of one of the electric discharge devices. A mercurycondensationpump illustrated generally by the numeral 2 provides meansfor evacuating the manifold 25. The low pressure side of the pump isconnected with the manifold 25 through a conduit 28. The upper portionof the mercury condensation pump 21 is preferably water-jacketed andsupplied with a cooling liquid, such as water, through suitable pipeconnections 29. The lower portion 30 of the pump provides a liquidreceiver for condensed mercury which is returned to the manifold when itrises above a predetermined level by the conduit 3|. The high pressureside of the mercury condensation pump discharges into a receiver tank 32through a conduit 33 including a vacuum tight valve 34. The receivertank 32 is maintained at a relatively low pressure compared withatmospheric by means of a pump 35 which has the intakey line 36 thereofcommunicating with the interior-of the receiver tank. The pump 35may beof any suitable type which will maintain a rough vacuum to relieve theload on the mercury condensation pump which maintains a good vacuum. Thepump 35 exhausts to the atmosphere through an exhaust port (not shown).

The vessels or containers of all the discharge devices lil to I5 arealso connected together beloW the level of the mercury surface of thecathodes thereof by a conduit system. As illustrated, this conduitsystem comprises a header or manifold 3l and a plurality of connectingconduits 38 each having one end communicating with the header 31 and atthe other end With a centrally located Well 39`formed in the bottom ofeach of the containers of devices Ill to I5. It is apparent that thisconduit system will maintain the liquid level in all of the containersequal.

t is believed that'the operation of the system described above Will bereadily understood. The pump 35 and the mercury condensation pump 21operate toA maintain the vesselsevacuated. In the process of evacuationvsome mercury vapor is drawn from the vessels of the discharge devices IDto l5. This mercury is condensed in a portion of the pump and returnedto the manifold 25 by the conduit 3l. iVith this return connection themercury may drip back into any one of the discharge devices. However,the conduit system communicating with each of the Vessels below thelevel of the mercury maintains the distribution of cathode liquid amongthe various discharge devices. It is apparent that if the mercurycondensation pump Were mounted at a lower level the exhaust manifold.This simplifies and reduces the cost of the equipment.

While I have described what I at present consider the preferredembodiment of my invention, it Will be obvious to those skilled in theart that various changes and modiiications may be made Without departingfrom my invention, and I, therefore, aim in the appended claims to coverall such changes and modifications as fall Within the true spirit andscope of my invention,

What I claim as new and desire to secure by Letters Patent of the UnitedStates is:

1. In combination, a plurality of electric discharge devices eachcomprising a container and a pair of principal electrodes positioned inthe container, one of said electrodes comprising a body of conductingliquid, a conduit system communicating with each of said containersbelow the normal level of the liquid electrode therein, a second conduitsystem communicating With each of saidj containers above the level ofsaid' liquid electrodes, pumping means having a connection communicatingwith said last mentioned conduit system for exhausting said containers,and means for returning to said containers cen-ducting. liquid removedfrom said containers by said pumping. means, said iirst mentionedconduit system serving to maintain uniform level of the liquidelectrodes in all of said discharge devices.

2. In combination, a plurality of electric. discharge devices eachcomprising a container and a plurality of principal electrodes. one ofWhich is. a body of mercury, means for mounting said containers so thatthe normal level of the mercury electrode is the same in all of saidcontainers, a conduit system communicating with each of said containersnear the upper end thereof, pumping means. connected with saidV conduitsystem for maintaining the interior of said containers at alow pressure,means for returning toY said containers mercury that is withdrawntherefrom by the operation of said pumping means, and means p formaintaining the surface of all of said mercury municating with each ofsaid containers above the normal level of the liquid electrodes, pumpingmeans connected with said conduit system for evacuating said dischargedevices, means associated with said pumping means forl returningconducting liquid which is removed from said containers by operation ofsaid pumping means

